*******Note that forecast and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.*********
...UPDATE...MONDAY OCTOBER 7 2024 12:01 PM EDT...
As of 11:55 AM EDT... Milton is now a category 5 hurricane with 160 mph maximum sustained winds and 925 mb minimum surface pressure. Should additional intensification occur between now and my next full update on the Atlantic tropics... I will be listing the latest intensity numbers below in table format.
**11:55 AM EDT... 160 mph maximum sustained winds... 925 mb minimum surface pressure
**2:00 PM EDT... 175 mph maximum sustained winds... 911 mb minimum surface pressure
**5:00 PM EDT… 180 mph maximum sustained winds… 905 mb minimum surface pressure
**8:00 PM EDT… 180 mph maximum sustained winds… 897 mb minimum surface pressure
...UPDATE...MONDAY OCTOBER 7 2024 11:00 AM EDT...
Milton is almost a category 5... while now featuring top-end category 4 sustained winds of 155 mph with 933 mb minimum central surface pressure.
...UPDATE...MONDAY OCTOBER 7 2024 10:34 AM EDT...
The surface and upper air charts valid for October 6 have now been added below. Meanwhile in the southwestern Gulf of Mexico... eastward-tracking Hurricane Milton continues to explosively intensify... and as of 9:05 AM EDT is packing category 4 150 mph maximum sustained winds and 940 mb minimum central surface pressure. This is an escalating and life-threatening situation for the northern Yucatan peninsula... particularly toward the north coast... where preparations need to be rushed to completion by midday today as weather conditions will deteriorate this afternoon and tonight... listen to your local news media and local government officials for advice including on evacuations to protect your life. The short-term increase in wind shear has not arrived as Milton's east track continues to have a southward deflection that is helping to keep the hurricane away from upper westerlies... with the upper westerlies continuing to enhance the hurricane's northern outflow... also noting this southward angle is increasing the potential for a direct strike on the north coast of the Yucatan peninsula. If current trends continue Milton could become one of the strongest measured category 5 hurricanes in Atlantic basin records within the next few hours. If a direct strike occurs with the northern Yucatan peninsula... this could result in rapid short-term weakening as Milton is a compact hurricane more sensitive to the size of the Yucatan. However even in this scenario the warm sea-surface temperatures and a favorable upper wind setup in the southeastern Gulf of Mexico could allow Milton to also rapidly recover while moving northeast toward southern and central Florida through Wednesday (the Milton section in the full update below has more on the favorable setup). And if Milton does not make landfall with the Yucatan... that furthermore increases the probability that the hurricane will be an intense category 4 or 5 whose intensity fluctuations are determined by structural changes such as eye wall replacement cycles... therefore I recommend interests in southern and central Florida should be preparing for this worst case scenario... continue to listen to your local news media and local government officials for more information.
...UPDATE...MONDAY OCTOBER 7 2024 12:18 AM EDT...
The discussion on areas of interest #38 to #40... tropical waves of low pressure lined up from the eastern Atlantic to Africa... are now published below
...UPDATE...SUNDAY OCTOBER 6 2024 11:23 PM EDT...
Satellite image of Hurricane Milton as of 0206Z:
Hurricane Milton continues to strengthen... and as of 11 PM EDT was upgraded to 90 mph maximum sustained winds with 977 mb minimum central surface pressure.
...SUNDAY OCTOBER 6 2024 10:30 PM EDT...
This post is initially released without discussion on areas of interest #38 to #40… tropical waves of low pressure lined up from the eastern Atlantic to Africa… due to the rapidly escalating situation with Milton in the Gulf of Mexico.
See Hurricane Kirk… Leslie… and Milton sections below for more information on the three concurrent hurricanes in the Atlantic basin. Milton is the most pressing situation as it will bring impacts primarily to the northern Yucatan peninsula tomorrow then Florida peninsula on Wednesday while rapidly strengthening. In addition noting that a major upper trough is setting up in the northwest Atlantic while producing a new frontal low west of Hurricane Kirk… will watch to see if the frontal low acquires tropical
character to the south of Newfoundland… toward the 26 deg C warm water around 40N latitude. Will add an area of interest for this situation in future updates if necessary.
HURRICANE KIRK... Southerly shear across Kirk… imparted by central Atlantic upper vorticity that approached from Bermuda… increased early… as such Kirk has been steadily weakening since Friday. Going forward Kirk will be steadily curving increasingly northeast than east in track while becoming entangled with the southwest quadrant of the current northeast Atlantic frontal cyclone. The hurricane is a little northeast of the previous forecast… however the 24-hr forecast point is the same and 48-hr forecast point is deflected south of the previous as the models have come into strong agreement on the southwest quadrant of the northeast Atlantic frontal cyclone keeping the track suppressed a little further south… eventually allowing what will be ex-Kirk to swing east into France instead of the British Isles by Wednesday. Regarding intensity… Kirk will be supported by the expansive upper divergence zone of a major northwest Atlantic upper trough now materializing from the merger between (1) the aforementioned central Atlantic upper vorticity that came in from the Bermuda area... (2) the current upper trough that recently entered the NW Atlantic from the NE US… (3) a high-latitude upper trough currently positioned between Greenland and Canada. Despite Kirk having a lower initial intensity relative to the prior forecast… the upper divergence zone should help Kirk remain a hurricane and thru 24 hours. A further position in waters below 26 deg C should then cause Kirk to complete transition into a non-tropical frontal cyclone by 48 hours.
Regarding impact to land areas:
(1) Coastal surf will continue across the Azores through 48 hours… becoming increasingly less associated with the current northeast Atlantic frontal cyclone and more associated with ex-Kirk… gusty winds cannot be ruled out for late Tuesday and early Wednesday with the south adjusted track for ex-Kirk
(2) Surf seen on the shores of Iceland and will now be totally associated with the northeast Atlantic frontal cyclone rather than ex-Kirk given the latest forecast track.
(3) Surf continues for the shores of the British Isles and mainland Western Europe… with gusty winds spreading onshore and across inland areas Tuesday and Wednesday from a one-two punch associated with the northeast Atlantic frontal cyclone landfall… then the landfall of ex-Kirk.
Update as of 5 PM EDT… Kirk has already weakened to 85 mph maximum sustained winds.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast********
0 Hr Position (1200Z Oct 6)... 100 mph maximum sustained wind major hurricane centered in the central Atlantic at 35.6N-47.7W
IOH 24 Hr Forecast (1200Z Oct 7)... 85 mph maximum sustained wind hurricane centered in the north Atlantic at 41N-39W
IOH 48 Hr Forecast (1200Z Oct 8)... Remnant frontal cyclone centered northeast of the Azores at 43N-25W
*****National Hurricane Center (hurricanes.gov) official forecast as of 11 AM EDT*************************
4-Day Position (1200Z Oct 10)… 40 mph maximum sustained wind remnant frontal low losing identity while while centered over NW Germany at 52.5N-9E
HURRICANE LESLIE... After previously dealing with the southern tip of mid-latitude eastern Atlantic upper vorticity late last week… Leslie is now in battle with a large chunk of the upper vorticity which has retrograded southwest to a position just northwest of the tropical cyclone. The shear imparted by the retrograding upper vorticity has allowed for Leslie to only gradually strengthen into a hurricane… and as the upper vorticity slowly fades from isolation from high-latitude cold air while moving in tandem with the hurricane I expect in the next 48 hours that Leslie will continue to gradually strengthen. The combo of the upper vorticity and southwest quadrant of the east Atlantic surface ridge support a continued west-northwest track of Leslie through that time. After 48 hours the latest model runs show the northwest/north Atlantic major upper trough that recurves Kirk northeastward also recurves the neighboring upper vorticity back east into Leslie… beginning westerly wind shear earlier than previously thought and so I show weakening by 72 hours. Between 72 and 96 hours the westerly wind shear greatly ramps up as the upper vorticity slides east overtop Leslie… with the shear direction then switching to northeasterly by 96 hours once the upper anticyclone currently over Milton begins to approach Leslie. I show rapid weakening from a category 2 hurricane to a top-end tropical storm due to the high shear… however do not show a 96-hr intensity even lower than this due to possible aiding split flow upper divergence between the back side of the departing upper vorticity and southeast side of the upper anticyclone. Noting the eastern convergence zone of the anticyclone may produce some blocking surface ridging to the west of Leslie… which is why the 96-hr west-northwest forward speed is reduced. By 120 hours a frontal cyclone is forecast to be positioned in the vicinity of Atlantic Canada… to be supported by the merger between the current central Canada deep-layer cyclone and central US/Canada border upper trough. This frontal cyclone should proceed to weaken any blocking surface ridge west of Leslie and turn Leslie increasingly north by 120 hours. Noting some models show Leslie re-intensify under the low shear/outflow associated with the core of the upper anticyclone… however with the 120-hr position still under the south side of the upper anticyclone I currently forecast some additional weakening under some easterly shear during that time.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1200Z Oct 6)... 90 mph maximum sustained wind hurricanes centered in the eastern tropical Atlantic at 13.3N-37.9W
IOH 24 Hr Forecast (1200Z Oct 7)... 105 mph maximum sustained wind hurricane centered in the eastern tropical Atlantic at 15.5N-40W
IOH 48 Hr Forecast (1200Z Oct 8)... 115 mph maximum sustained wind major hurricane centered in the central tropical Atlantic at 18.5N-42W
IOH 72 Hr Forecast (1200Z Oct 9)... 100 mph maximum sustained wind hurricane centered in the central Atlantic at 21N-46W
IOH 96 Hr Forecast (1200Z Oct 10)… 70 mph maximum sustained wind tropical storm centered in the central Atlantic at 22.5N-47.5W
IOH 120 Hr Forecast (1200Z Oct 11)… 60 mph maximum sustained wind tropical storm centered in the central Atlantic at 24N-50W
*****National Hurricane Center (hurricanes.gov) official forecast as of 5 PM EDT*************************
5-Day Position (1800Z Oct 11)… 60 mph maximum sustained wind tropical storm centered in the central Atlantic at 24.1N-51.7W
TROPICAL STORM MILTON (RECENTLY UPGRADED TO HURRICANE MILTON)... The cyclonically curled surface trough of low pressure spanning the southern Gulf of Mexico and northwestern Caribbean has undergone rapid changes this weekend. The comma head of this system… positioned in the southwestern Gulf of Mexico… became tropical depression fourteen then Tropical Storm Milton on Saturday while the remainder eastern tail of this system became a surface low that shifted north into the eastern Gulf while cyclonically orbiting Milton. Milton likewise was on an initial south drift while orbiting the neighboring eastern Gulf surface low. This drift appears to have setup Milton for today’s recent rapid intensification into a hurricane while the more south position placed it into a lower shear environment away from the upper westerlies associated with the current south-central US upper vorticity. Moreover the upper westerlies appear to be enhancing Milton’s northern outflow. Recently Hurricane Milton has turned east while likely now being strong/tall enough to respond to the upper westerlies.
Going forward the current central US/Canada upper trough will help to join the central Canada deep-layer cyclone with the south-central US upper vorticity… allowing the upper vorticity to finally be swung east by the deep-layer cyclone. In the next 24 hours the upper vorticity initially approaches Milton while remaining tilted SW/NE… which should increase westerly shear over the hurricane as it slides east just offshore of the northern Yucatan. Therefore my forecast assumes some additional strengthening possible in the short-term followed by weakening by 24 hours… thus keeping the net intensity at 24 hours the same as it is now. Between 24 and 72 hours the upper vorticity takes on a more north-south tilt while it continues to arc around the Canadian deep-layer cyclone… shifting the upper flow over Milton from westerly to a less shearing and more divergent southwesterly flow. Combined with the warm 30 deg C southeastern Gulf of Mexico waters… the upper divergence will likely aid Milton in developing a robust thunderstorm core whose latent heat release allows for a local outflow enhancing warm core upper anticyclone. The upper southwesterly flow will likely enhance the northern outflow of the local upper anticyclone… resulting in a dangerous setup where Milton rapidly intensifies. Noting the upper southwesterly flow bends Milton’s track northeastward into the Florida peninsula. Sometime either just before… during… or just after passage over Florida… the steering upper vorticity is coaxed back into a SW/NE tilt while dragged by the Canadian cyclone’s east shift into Atlantic Canada. This results in an increase in westerly wind shear and deflection of the track to a more east and less north angle. And by day 5 a surface ridge builds north of Milton and in the wake of the Atlantic Canada system… slowing the east progress of this system which further increases the shearing effect of the upper westerlies. The NHC forecast and I agree on Milton explosively intensifying into a category 4 hurricane peak before shear increases toward the end of the 5-day period… the difference is the NHC forecast calls for shear to start just before landfall with Florida such that the landfall intensity is a weaker but still dangerous category 3… while I currently forecast Milton to be continuously strengthening through the category 4 wind scale thru landfall time.
Regarding impact to land areas:
(1) Due to Milton’s recent rapid development… interests across the northern Yucatan peninsula should be rushing preparations to completion by no later than midday tomorrow for hurricane force wind and coastal surf… as weather conditions will deteriorate by tomorrow afternoon and evening.
(2) I recommend interests across the Florida peninsula… particularly southern and central areas… to begin preparing for potentially severe damage from strong hurricane force winds and coastal surge to arrive by Wednesday… the worst of which will be the on the west-facing coast but with significant impacts across inland areas and the east-facing coast as Milton would be moving quickly through the area and not have much time to weaken after the expected west coast landfall. Listen to your local news media and local government officials for more information in the days ahead.
(3) Western Cuba… the Florida Keys… and the northwestern Bahamas will also see coastal surf… along with possible outer heavy rainfall bands bringing gusty winds. Western Cuba is expected to see these impacts by Tuesday… with the Florida Keys by late Tuesday and Wednesday… and the northwestern Bahamas by Thursday.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1800Z Oct 6)... 85 mph maximum sustained wind hurricane centered in the southwestern Gulf of Mexico at 22.4N-93.8W
IOH 24 Hr Forecast (1800Z Oct 7)… 85 mph maximum sustained wind hurricane centers just offshore of the northern Yucatan peninsula at 22.5N-89.5W
IOH 48 Hr Forecast (1800Z Oct 8)… 100 mph maximum sustained wind hurricane centered in the southeastern Gulf of Mexico at 24N-85W
IOH 60 Hr Forecast (0600Z Oct 9)… 130 mph maximum sustained wind major hurricane centered offshore of southwestern Florida at 26N-83W
IOH 72 Hr Forecast (1800Z Oct 9)… 95 mph maximum sustained wind hurricane centered over east-central Florida at 27.8N-81.2W
IOH 96 Hr Forecast (1800Z Oct 10)… 65 mph maximum sustained wind tropical storm centered in the western Atlantic at 30N-75W
IOH 120 Hr Forecast (1800Z Oct 11)… 40 mph maximum sustained wind tropical storm centered in the western Atlantic at 30N-71.5W
*****National Hurricane Center (hurricanes.gov) official forecast as of 5 PM EDT*************************
Peak strength (1800Z Oct 8)… 145 mph maximum sustained wind major hurricane centered in the southeastern Gulf of Mexico at 23.6N-86.9W
Landfall (1800Z Oct 9)… 120 mph maximum sustained wind major hurricane centered just southwest of Tampa Bay Florida at 27N-83.1W
5-Day Position (1800Z Oct 11)… 65 mph maximum sustained wind frontal cyclone centered west-southwest of Bermuda at 31.4N-68.8W
AREA OF INTEREST #38... The tropical wave of low pressure which emerged into the Atlantic from Africa on Friday... and currently positioned southwest of the Republic of Cabo Verde Islands... has lost all thunderstorm activity while losing competition for surface inflow from neighboring Hurricane Leslie to the west and area of interest (AOI) #39 to the east... therefore cancelling this wave as an area of interest for tropical development.
AREA OF INTEREST #39... A tropical wave of low pressure is currently emerging into the eastern tropical Atlantic from the west coast of Africa. The cloudiness showed less thunderstorm activity in the morning hours but still had cyclonic curvature... however by the afternoon and evening thunderstorms have redeveloped on the east side of this feature along coastal Africa... waters just offshore... and areas just inland. Therefore maintaining this tropical wave as an area of interest for possible development in the days ahead. Interestingly the models over the weekend dropped developing this wave... and after 2 PM EDT Saturday the NHC switched to having area of interest #40 to the east as the tropical wave of interest as some models began switching to developing that wave. I have lowered my peak odds of development to 20% for this area of interest given the loss in model support. After day 4... residual upper vorticity in the eastern Atlantic merges with the northwest/north Atlantic major upper trough that is currently recurving Kirk northeastward... with the merger resulting in an eastern Atlantic upper trough which dives south due to the force of a mid-ocean upper anticyclone that will be over Leslie by days 4 and 5 (see Leslie section above for more info on the upper anticyclone). The divergence zone of the eastern Atlantic upper trough erodes the steering east Atlantic surface ridge... causing this tropical wave to slow down its westward progress. Moreover the southwest tail of the upper trough may bend the west track of this tropical wave more north. Wind shear and/or outflow disruption imparted by the southwest tail of the upper trough may make conditions more difficult for development... therefore by day 5 I lower odds of development to 10%.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
Formation chance through 4 days... 20% (eastern tropical Atlantic near 12.5N-35W)
Formation chance days 4 to 5... 10% (eastern tropical Atlantic near 14N-38.5W)
*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT*************************
Not in the official outlook
AREA OF INTEREST #40... In the wake of area of interest (AOI) #39 is a large field of disorganized cloudiness... showers... and thunderstorms across western and central Africa... and somewhere within this location is the next tropical wave of low pressure expected to enter the Atlantic from the west coast of Africa in about 3 to 4 days. Some model runs have switched to developing this wave... and over the weekend the NHC has switched to highlighting this wave as an area of interest for possible development in the days ahead. Note that as the wave emerges from western Africa... a southward diving upper trough is expected to be present in the eastern Atlantic (as noted in the above AOI #39 section) which will likely bend the track of this wave northwestward toward the Republic of Cabo Verde Islands. Because the tropical wave is currently not well defined... and because not all models agree on developing this wave... my peak odds of development are set at 20% which is slightly less than the NHC outlook as of this writing. Interests in the Republic of Cabo Verde Islands should be aware of this area of interest as there is some potential for gusty wind... heavy rain... and coastal surf impact by Friday.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
Formation chance through 5 days... 20% (just southeast of the Republic of Cabo Verde Islands near 14N-21.5W)
*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT*************************
Formation chance through 48 hours... 0%
Formation chance through 7 days... 30%
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/).
0000Z (Oct 6) CMC Model Run...
**For Hurricane Kirk... gradually turns increasingly east into the northeast Atlantic while transitioning into a frontal cyclone and makes landfall on the west coast of France just after 90 hours
**For Hurricane Leslie... weakens back to a tropical storm while moving west-northwest to 17N-41.8W through 48 hours… subsequently turns north and regains hurricane strength at 90 hours at 22N-46.5W… weakens back to a tropical storm at 126 hours while located near 25.5N-47.5W… subsequently merges with cold front while curving northeast to 31.2N-38.8W through 168 hours
**For Tropical Storm Milton... gains hurricane strength through 54 hours while drifting ESE into the waters just offshore of the northwestern Yucatan peninsula… moves ENE then NE into the eastern Gulf of Mexico through 108 hours while becoming a potentially intense hurricane… begins weakening thereafter and makes landfall with SW Florida at 126 hours… as a tropical storm gradually transitioning into a non-tropical frontal low moves ENE into the waters north of the NW Bahamas then reaches 31.5N-71.5W by 168 hours
**For area of interest #38... no development shown
**For area of interest #39... no development shown
**For area of interest #40… no development shown
0000Z (Oct 6) ECMWF Model Run...
**For Hurricane Kirk... gradually turns increasingly east into the northeast Atlantic while transitioning into a frontal cyclone and makes landfall on the west coast of France between 84 and 90 hours
**For Hurricane Leslie... weakens back to a tropical storm while moving west-northwest to 21.5N-47.5W through 96 hours… curves north and weakens to a remnant low near 25N-50W at 132 hours… fading remnant low reaches 30N-46W by 168 hours
**For Tropical Storm Milton... gains hurricane strength through 54 hours while drifting ESE then east into the waters just offshore of the northern Yucatan peninsula… subsequently curves ENE then NE into the waters just offshore of SW Florida shortly after which time it begins to weaken… makes landfall just south of Tampa Bay FL at 96 hours as it weakens to a tropical storm and passes just north of the NW Bahamas at 108 hours… subsequently transitions into a fading remnant frontal low that drifts ESE to 26.5N-71W through 168 hours
**For area of interest #38... no development shown
**For area of interest #39... no development shown
**For area of interest #40… no development shown
0600Z (Oct 6) GFS Model Run...
**For Hurricane Kirk... gradually turns increasingly east into the northeast Atlantic while transitioning into a frontal cyclone and makes landfall on the west coast of France just after 81 hours
**For Hurricane Leslie... weakens back to a tropical storm while moving west-northwest to 18.5N-44W through 57 hours… regains hurricane strength near 22.5N-50W at 105 hours after which time it turns north and weakness back to a tropical storm near 24.5N-51.5W at 129 hours… the tropical storm then becomes quasi-stationary in this region through 168 hours
**For Tropical Storm Milton... gains hurricane strength through 48 hours while drifting ESE then east into the waters just offshore of the northern Yucatan peninsula… subsequently curves ENE then NE for a hurricane strength landfall just north of Tampa Bay FL at 84 hours… while weakening to a tropical storm bends ESE onto the NE coast of Florida at 96 hours and into the waters north of the NW Bahamas at 108 hours… proceeds to gradually weaken to a quasi-stationary remnant low near 29N-72.5W by 168 hours
**For area of interest #38... no development shown
**For area of interest #39... no development shown
**For area of interest #40… tropical wave emerges from west coast of Africa at 87 hours and becomes a possible tropical depression centered just NE of the Republic of Cabo Verde Islands by 123 hours… the weak tropical cyclone becomes a remnant low while continuing NW to 22.5N-26.5W through 168 hours
0600Z (Oct 6) NAVGEM Model Run...
**Not available at above-mentioned source
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